Development of the PBF-LB/M Workflow for Ti-Al through Improvement of Thermal Management by Multi-Laser Scan Strategy

High temperature intermetallic alloys such as Ti-48Al-2Cr-2Nb are attractive for aero engines and energy components because of their low density, high strength at elevated temperatures, and good oxidation resistance. Their brittle behavior and strong thermal sensitivity make processing difficult. Laser powder bed fusion of metals (PBF-LB/M) offers the design freedom needed for advanced lightweight structures, but the processing of titanium aluminides (Ti-Al) often leads to crack formation, porosity, and unstable build conditions.
The thesis focuses on the development and analysis of a thermally stabilized multi-laser PBF-LB/M process for Ti-48Al-2Cr-2Nb. Experimental investigations and numerical simulations are used to study temperature fields, residual stresses and aluminum evaporation. Based on these results, process parameter windows and multi-laser strategies are derived to improve temperature homogeneity and melt pool stability. The results of the study provide a robust foundation for machine users, material developers and design engineers seeking to qualify difficult-to-weld mate-rials for industrial application by PBF-LB/M processes.